A recent wireless communication system employs an adaptive modulation scheme for switching modulation and coding schemes for a radio signal, depending on varying transmission path environment.
For example, in a next generation PHS (next generation Personal Handy-phone System) employing the OFDMA (Orthogonal Frequency Division Multiple Access) system, a mobile station determines a modulation and coding scheme, based on an SINR (a signal to interference and noise ratio) which indicates signal quality of a received communication signal, and sends a modulation and coding scheme request (MR: MCR request) containing the determined modulation and coding scheme (MCS) to a base station (see the non-patent document 1 mentioned below).
In such a wireless communication system, generally, modulation and coding scheme for a communication signal to be sent from a transmitting device to a receiving device is determined, based on signal quality subjected to received power control through AGC (automatic gain control).